Strap stretching device



Patented Nov. 1, 1932 UNITED STATES PATENT OFFICE CHESTER M. MACCHESNEY, RALPH H. NORTON, AND JOHN EKEBN DEPT, OF CHICAGO,

ILLINOIS, ASBIGNOBS TO ACME STEEL COMPANY, OF CHICAGO, ILLINOIS, A CORPORA- TION OF ILLINOIS STRAP STRETCHIHG DEVICE Application filed May 10,1928. Serial No. 276,659.

This invention relates to improvements in strap stretching devices and its purpose is to provide an improved device for stretching or tightening a strap or other binder around a box, package or other article to be reinforced. The principal object of the invention is to provide a simple and economical device capable of being conveniently operated for pulling a strap or hinder into taut condition around the package or other object to be reinm forced thereby, preliminary to uniting the ends of the strap or hinder by means of a seal or other device or to fastening the ends to the ackage by nailing or other means.

urther object of the invention is to provide a strap stretching device having improved gri ping means for engaging and holding the en s of the strap without requiring manual 0 eration of the gripping-devices. A further 0 ject of the invention is to provide a strap stretching device capable of being conveniently operated by one hand of the operator to stretch the strap- A further object is to provide a strap stretching device comprising means for readily releasing the device from the strap after it has been rendered taut. Another object is to provide a device capable use on a narrow or curved package. A further object of the invention is to provide an improved strap stretching device comprisinga pair of strap gripping devices adapted to move away from each other in effecting the stretching of the strap, thereby providing certain portions of the strap which overlap each other to permit the application of a fastening seal for securing the ends of the strap together. Still anothr'object of the invention is to provide a strap stretching device having improved operating mechanism for effecting the relative separation of the strap gripping devices. Other objects relate to various features of construction and arrangement which will appear more fully hereinafter.

The nature of the invention will be understood from the following specification taken with the accompanying drawings in which one embodiment is illustrated. In the drawlngss Figure 1 shows a top plan view of the improved strap stretching device;

Fig. 2 shows a side elevation of the device in position to stretch a strap around a box;

Fig. 3 is a detailed sectional view taken on the line 33 of Fig. 1;

Fig. 4 shows a detailed sectional view taken on the line 4-4 of Fig. 1;

Fig. 5 shows a side elevation of a portion of the strap stretching device with a part of the casing thereof removed to illustrate the operating mechanism.

Fig. 6 shows a vertical section taken on the A line (36 of Fig. 5; and

Fig. 7 shows a detailed section taken on the line 7-7 of Fig. 5.

The strap stretching device illustrated in the accompanying drawings comprises a casing or frame member 10 having formed integrally therewith a handle 11 and having detachably secured thereto a casing section 12 which is normally secured to the casing 10 by means of screws 13 to form a. complementary part thereof. The handle 11 is provided with an upwardly-extending projection 11 to prevent the forward movement of the hand of the operator onto the body portion of the casing 10, the upper or outer surface of which is curved to conform substantially to the arc of the circle. The casing 10 has a lower flat surface 1O lying in the same plane with the lower flat surface 12 of the complementary casing section 12 and these surfaces are adapted to extend horizontally in a. plane substantially parallel with the general direction of the handle 11. These surfaces are adapted to extend parallel to and may rest upon the upper surface of a box or package 14 about which a metal strap or binder 15 is to be stretched by the operation of the siretching device. The lower forward portion of the casing section 12 has projecting laterally therefrom a foot or flange 16' which extends horizontally above the surface of the box 14 and is adapted to form a grippingv member 17 .is curved as shown at 17 ooncen trically with the curvature of the in 18 and this portion of the gripping mem er lies beneath an overhanging ange 21 formed on the casing 12 and having a curvature corresponding to that of the end of the gripping member, thus providing a support for the gripping member indepcndentl of that afforded by the pin 18. One on 15" of the strap 15 is adapted to lie in contact with the foot or flange 16 and to be engaged by the serrated gripping surface 17 of the gripping member. The gripping member is normally moved into engagement with the strap 15 by means of'a coil spring 22 which en ages a recess 23 formed in the gripping mem er and bears against a flange 24 formed on the cas- 12. It will .be noted that the serrations gripping member and that the gripping member is inclined downwardly and toward the right from the axis of the pin 18 so that the gripping surface lies at one side of a vertical Elane passing through the axis of the pin 18.

y this arrangement of the gripping member a pull on the strap 15 towards the left,

as viewed in Fig. 2, tends to tighten the grip of the movable gripping member 17 upon the upper surface of the strap and to press it more tightly against the foot or ange 16, whereas a pull on the strap 15 toward the right, as viewed in Fig. 2, readily releases the strap. To secure these results mostv efliciently the gripping member should be mounted at such an angle that its serrated gripping surface will lie at least partially within a line passing through the pivotal axis of the gripping member and making an angle of 60 with the surface of the strap and no part of the gripping surface should extend inwardly beyond a line passing through said pivotal axis normal to the strap. This gripping dog is described and claimed in the copending application of John Ekern 0121;, Serial No. 276,564, filed May 10, 1 928. The casing members 10 and 12 are provided with a horizontal guideway 25 of rectangular cross section adapted to be slidably engaged by a rack bar 26 which is formed at one end with an enlarged head 27 and which is provided at the other end with a detachable screw 28 for retaining the rack bar in its guideway. The head 27 carried by the rack ar 26 is provided with ahorizontally extending foot or flange 30 adapted to rest upon the upper surface of the box 14 and this head carries a pivotally mounted gripping member 31 having a serrated lower surface 31" which is ada ted to cooperate with the upper surface 0 the foot or flange 30 to grip the end 15" of the strap which is opposite to the end 15 engaged by the gripping member 17. The gripping member 31 is pivotally mounted on a pin 32 which engages an aperture 33 in the head 27 and is secured are formed on a plane surface of the in position by a set screw 34. The head 27 is further provided with an overhanging curved flange 35 adapted to conform to the which is adapted to receive the strap 15 adjacent the ends 15 thereof, as shown in Fig. 2. The serrated gripping surface 31 of the gripping member is displaced laterally from a vertical plane containing the axis of the pin 32 and this gripping surface is normally forced downwardly toward the foot or flange ,30 by the operation of a coil spring 36 which engages a recess 37 in the gripping member and also the lower end of a recess 38 in the flange 35, this recess 38 being closed by a set screw 39. The upper surfacer30 of'the foot or flange 30 is preferably inclined downwardly and toward the right, as Viewed in Fig. 2 and the fiat surface of the gripping member on which the serrations 31 are formed has a similar inclination as more fully described in the copending a plication above referred to. The end 15 0 the strap may be passed into position on the surface 30 of the flange 30 beneath ripping member 31 without manually upholding the member 31 against the compression of the spring 36, and when a pull is exerted on this strap the tightness of the grip of the serrated surface 31 on the strap tends to increase due to the fact that this serrated surface is disposed on the opposite side of a vertical plane containing the axis of the pin 32 from the oint where the pull is exerted on the strap. aving passed-the strap into engagement with the flange 30 and the gripping member 31, it is carried beneath the foot or flange 16 which has an inclined under surface 16, and is then passed around the box 14 and brought u over the opposite edge thereof in such at why that the strap overlaps the end '15" at the point 15 and the strap 15 is then passed into engagement with the slot 31 in the gripping member 31 and the end 15" thereof is then placed in position on the foot or flange 16 to be grip ed by the pivoted gripping member 17. 'l ie parts are then in readiness for the stretching of the strap which is brought about by effecting a relative movemerit of the casin members 10 and 12, and the head 27 there y causing a separation of the gripping members 17 and 31 and causing the strap 15 to be stretched with its ends overlapped to permit a seal to be applied at the point 15 where the ends of the stra are in contact with each other or to permit these ends to be otherwise secured.

The relative movement of the two pairs of gripping members by which the" stra is stretched around the box or other pac age is efieoted by a certain mechanism engaging the rack bar 26. This mechanism comprises a pinion which meshes with the teeth of the racjr bar and which is mounted on a shaft 41 having hearings in the opposite walls of the casing sections 10 and 12, as shown in Fig. 6. The shaft 41 has a head 41 which is flattened on one side as shown at 41 in Fig. 2, to enga e the flange 24 so that rotation of this sha is prevented. The opposite reduced end of the shaft is threaded for engagement by a nut 42 so that it assists the screws 13 in securin the casing members 10 and 12 together. T e hub of the pinion 40 carriesan integrally formed ratchet wheel 43 by which the pinion is rotated and the teeth 43 of this ratchet wheel are adapted to be engaged by a pawl 44 which is located within the chamber of the casing members and pivotally connected by a pin 45 with an operating lever 46 which is pivotally mounted on a pin 47 carried by the casing members. The 0 crating lever 46 is located directly beneath the handle 11 and is provided with a downwardly projecting lu 46 to limit the forward movement of the ngers of the operator which are adapted to engage this operating lever when the palm of the hand is in engagement with the handle 11. The upward movement of the operating lever 46 is adapted to be limited by a lug 46 which engages a lug 48 formed on the underside of the upper portion of the casing 10. Upon upward movement of the lever 46 from the positions illustrated in Figs. 2 and 5, the pawl 44 moves downwardly and effects rotation of the ratchet wheel 43 and the inion 40, the pawl 44 being normally moved into engagement with the ratchet teeth by the action of certain mechanism engaging the upper end thereof. For this purpose, the pawl 44 is provided with a projecting head 44 located above the pivot pin 45 and this .head is provided with a socket 49 which is loosely engaged by a pin 50, the lower end of which loosely engages another socket 51 formed in the upper side of a dentent 52 which is ivoted on a pin 53 extending horizontal y between the walls of the casing members 10 and 12. The detent 52 has a tooth 52 adapted to engage the teeth of the ratchet wheel to prevent reverse rotation thereof. A coil spring 55 is mounted on the pin with its lower end engaging a collar 56 carried by the pin and with its upper end engaging the underside of the head 44 carried by the pawl 44. By this arrangement, the coil spring serves not only to force the pawl 44 into en gagement with the teeth of the ratchet wheel but it also acts normally to maintain the tooth 52 of the detent in engagement with a tooth of the ratchet wheel. When the pawl is operated to rotate the ratchet wheel the detent rides over the teeth. of the ratchet wheel and engages a tooth in a newposition to hold the ratchet wheel against reverse rotation during a reverse movement of the operating lever 46. To permit the release of the ratchet wheel and to allow a relative return movement of the casing and the rack bar 26 after these parts have been actuated to effect the relative separation of the two sets of gripping members the detent 52 is rocked upwardly about its pivot 53 and the pawl 44 is simultaneously moved out of engagement with the ratchet teeth. This operation is effected by'a releasing member 60 mounted on a shaft 61 and having one arm 61 to engage the underside of a projection 52" formed on the detent. The release member 60 is further provided with an upwardly extending part 61" which is adapted to engage the inner face of the arm of the pawl 44. When the shaft 61 is rotated in a clockwise direction, as viewed in Fig. 5, the parts 61 and 61 of the release member serve to efl'ect simultaneous disengagement of the detent 52 and the pawl 44, res ectivcly, with the teeth of the ratchet whee 43. This 0 eration is effected by a thumb lever 63 w ich is secured on the projecting end of the shaft 61 by a cotter pin 64, as shown in Fig. 2. The upper curved extremity 63 of this thumb lever is in convenient position to be engaged by the thumb of the hand which rests on the handle 11 so that one hand of the operator may be employed to effect the operation of stretching the strap and also to release the stretching mechanism after the strap has been rendered taut. As heretofore indicated, the release of the ends of the strap from the gripping members 17 and 31 is effected by such relative movement of the strap and gripping member as will tend to increase the inclination of the axis of the gripping member with respect to a vertical plane passing through its pivotal axis. Inasmuch as the grigping members require the operation of no a usting screws or other auxiliary devices for causing them to grip the strap and since they may be released merely by effecting relative movement of the gripping members with respect to the strap in a direction contrary to that whichvtends to increase the grip, it will be apparent that the strap stretching device may be quickly operated for engaging and releasing a strap and that one hand of the operator is free to move the strap into and out of engagement with the gripping members which are self-grippin g and self-releasing.

Although one form of the invention has been shown and described by way of illustration, it will be understood that it may be constructed in various other forms within the scope of the appended claims.

lVc claim 2 1. The combination in a strap stretching device, of a pair of relatively movable members, gripping members carried by each of said first named members and constructed to I30 grip the ends of a flat metal strap with said en s overlapping one above the other, and means for moving said first named members away from each other for drawing said strap taut around a package and maintaining said overlapping portions in taut condition.

2. The combination in a strap stretching device, of a pair of relatively movable members each having a stra engaging surface, a pair of gripping mem ers each pivoted on one of said first named members and adapted to grip a flat metal strap seated on one of said surfaces, said gripping devices being constructed to grip the ends of a flat metal strap encircling a package with the ends of said strap overlapping each other one above the other, said gripping members being inclined away from each other from their pivotal axes, and operating mechanism carried by one of said first named members for effecting movement of said first named members away from each other to draw said strap taut around said package and create tension in the overlapping portions thereof.

3. The combination in a strap stretching device of a frame, a member movable with respect to said frame, said frame and said member each having a gripping surface, and gripping members pivoted on said frame and said member for cooperation with said surfaces to grip a strap, one of said pivoted gripping members having a slot to permit said strap to pass therethrough.

4. The combination in a strap stretching device for drawing a strap taut around a. package with the ends thereof overlapping one above the other, of a pair of relatively movable members each having a gripping surface, means for effecting relative movement of said members away from each other to stretch said strap, a gripping member pivoted on each of said first named members to engage a strap seated on one of said gripping sur faces, and means tending normally to move said gripping members into engagement with said strap, said gripping members being. inclined away from each other from their pivotal axes toward said grippingsurfaces.

5. The combination in a strap stretching device of a member having a laterally projecting flange provided with a strap engaging surface, a gripping member pivoted on sai first named member to engage a strap seated on' said surface, a supporting flange carried by said first named member to engage said gripping member and permit movement thereof, and a spring interposed between a part of said supporting flange and said pivoted gripping member for moving said grippin member normally into engagement with sai strap.

6. The combination in a strap stretching device of a frame, a rack bar havin movement in said frame, means carried y said bar'and said frame for engaging a strap,

means carried by said frame including a ratchet wheel for effecting movement of said rack bar, a pawl adapted to engage said ratchet wheel, a handle mounted in fixed position on said frame, and means for relative movement with respect to said handle for efleclting a reciprocating movement of said 7. The combination in a strap stretching device of a frame, a rack bar having movement in said frame, means carried by said bar and said frame for engaging a strap, means carried by said frame including a ratchet wheel for effecting movement of said rack bar, a pawl adapted to engage said ratchet wheel, a detent engaging said ratchet wheel common means tending normally to maintain said pawl and said detent in engagement with said ratchet wheel, and means for operating said awl.

P 8. The combination in a strap stretching device of a frame, a rack bar having movement in said frame, means carried by said bar and said frame for engaging a strap, means carried by said frame including a ratchet wheel for effecting movement of said rack bar, a pawl adapted to engage said ratchet wheel, a detent engaging said ratchet wheel, common means tending normally to maintain said pawl and said detent in engagement with said ratchet wheel, means for operating said pawl, and means for simultaneously disengaging said pawl and said detent from said ratchet wheel.

9. The combination in a strap stretching device of a frame, a bar movable in said frame, means carried by said bar and said frame for gripping a strap, means including a ratchet wheel for moving said bar, a pawl and a detent adapted to engage said ratchet wheel, means including a spring interposed between said pawl and said detent for causing them to engage said ratchet wheel, and a lever pivoted on said frame for operating said pawl.

10. The combination in a strap stretching device of a frame, a bar movable in said frame, means carried by said bar and said frame for gripping a. strap, means including a ratchet wheel for moving said bar, a pawl and a detent adapted to engage said ratchet wheel, means including. a spring interposed between said pawl andsaid detent for causin g them to engage said ratchet wheel, a. lever pivoted on said frame for operating said pawl, a releasing member mounted on said frame for engaging said pawl and said detent, and means for operating saidreleasing member.

11. The combination in a strap stretchin device of a frame, a bar movable in sai frame, means carried by said bar and said frame for gripping a strap, means including a ratchet wheel for moving said bar, a pawl and a detent adapted to engage said ratchet wheel, means including a spring interposed between said pawl and said detcnt for causing themto engage said ratchet wheel, a lever pivoted on said frame for operating said pawl, a releasing member mounted on said frame for 'engaging said pawl and said de tent, and a thumb lever for operating said releasing member.

12. The combination in a strap stretching device, of a. pair of relatively movable members, means for effecting such relative movement, a flange projecting laterally from each of said members, a gripping member pivoted on each of said first-named members to engage 1 a strap seated on the surface of the adjacent flange, and a supporting flange carried by each of said first-named members to engage the end of one of said gripping'members opposite the strap-engaging portion thereof to support it independently of its pivot, said gripping members being inclined toward said flanges with respect to lihes passing normally to said flanges through their pivotal axes so that relative movement of said members in one direction causes said gripping members 7 to increase their grip upon said strap while relative movement of said first-named menr bers in the opposite direction causes said gripping members to release said strap. In witness whereof, we have subscribed our names.

CHESTER M. MACCHESNEY. RALPH H. NORTON. JOHN EKERN OTT.

DlSOLAI'MER 1,885,742.Ohester M. MacUhesney, Ralph H. Norton, and John Ekem Ott, Chicago,

Ill. STRAP Sran rcnme Dnvrcn. Patent dated November 1, 1932. Disclaimer filed April 21, 1938, by the assignee, Acme Steel Company.

Hereb enters this disclaimer to claim 1 in said 5 ecification.

[gfiicial Gazette May 17, 1.938.] p

wheel, means including a spring interposed between said pawl and said detcnt for causing themto engage said ratchet wheel, a lever pivoted on said frame for operating said pawl, a releasing member mounted on said frame for 'engaging said pawl and said de tent, and a thumb lever for operating said releasing member.

12. The combination in a strap stretching device, of a. pair of relatively movable members, means for effecting such relative movement, a flange projecting laterally from each of said members, a gripping member pivoted on each of said first-named members to engage 1 a strap seated on the surface of the adjacent flange, and a supporting flange carried by each of said first-named members to engage the end of one of said gripping'members opposite the strap-engaging portion thereof to support it independently of its pivot, said gripping members being inclined toward said flanges with respect to lihes passing normally to said flanges through their pivotal axes so that relative movement of said members in one direction causes said gripping members 7 to increase their grip upon said strap while relative movement of said first-named menr bers in the opposite direction causes said gripping members to release said strap. In witness whereof, we have subscribed our names.

CHESTER M. MACCHESNEY. RALPH H. NORTON. JOHN EKERN OTT.

DlSOLAI'MER 1,885,742.Ohester M. MacUhesney, Ralph H. Norton, and John Ekem Ott, Chicago,

Ill. STRAP Sran rcnme Dnvrcn. Patent dated November 1, 1932. Disclaimer filed April 21, 1938, by the assignee, Acme Steel Company.

Hereb enters this disclaimer to claim 1 in said 5 ecification.

[gfiicial Gazette May 17, 1.938.] p 

